title: The cortical excitability profile of temporal lobe epilepsy.
abstract: OBJECTIVE
  Transcranial magnetic stimulation (TMS) was used to characterize measurable changes of cortical excitability in patients who were undergoing medical and surgical management of temporal lobe epilepsy (TLE) to investigate whether these alterations depended on timing of achieving seizure control throughout the course of illness and method of management.
  
  
  METHODS
  Eighty-five patients with TLE divided into (1) drug naive-new onset, (2) early medically refractor, and (3) late medically refractory, (4) early seizure-free on antiepileptic drugs, and (5) late seizure-free on antiepileptic drugs, (6) postoperative refractory, and (7) postoperative seizure-free groups were studied. Motor threshold (MT) and paired-pulse TMS at short (2, 5, 10, and 15 msec) and long (100-300 msec) interstimulus intervals (ISIs) were measured. Results were compared to those of 20 controls.
  
  
  RESULTS
  A significant interhemispheric difference was observed early at onset prior to starting medication, with higher cortical excitability in the hemisphere ipsilateral to the seizure focus, whereas the unaffected hemisphere was normal. After that, cortical excitability was higher in both hemispheres in the refractory groups (medical and postoperative) compared to the seizure-free and drug-naive groups (p < 0.05). This effect was most prominent at the long ISIs.
  
  
  CONCLUSIONS
  Changes in cortical excitability seen in patients with TLE are influenced by the course of the disease. The alterations that occur due to epilepsy are closely related to course of illness and degree/timing of seizure control. Successful management leads to resolution of this cortical hyperexcitability in a similar fashion regardless of method: medication (intact generator, but modulated by drugs) or surgery (generator removed).
authors.affiliation: Department of Clinical Neurosciences, St Vincent's Hospital, Fitzroy, Victoria, Australia; Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia; Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Radwa A B
authors.initials: RA
authors.lastname: Badawy
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Vogrin
authors.forename: Alan
authors.initials: A
authors.lastname: Lai
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Cook
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D002540:Cerebral Cortex / Q000187:drug effects / Q000601:surgery; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000188:drug therapy* / Q000601:surgery*; D019054:Evoked Potentials, Motor / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000927:Anticonvulsants
keywords: Cortical excitability; Refractory seizures; Seizure freedom; Temporal lobe epilepsy; Transcranial magnetic stimulation